Cities worldwide face unprecedented challenges: extreme heat, intense flooding storms, rising ocean levels, growing populations, inequity combined with declining human and ecosystem health. Future proofing cities is about designing built environments, public spaces, services and policies that make our communities more adaptable and resilient in the face of these challenges. Green infrastructure involves capturing stormwater as a resource, and using it to grow plants in, on and around buildings. Green infrastructure remains a fundamental and underutilized opportunity for us to secure a healthier and more prosperous future. At CitiesAlive hundreds of experts will come together to share new research, design practices, products, policies and services that help all of us advance our collective ability to future proof our cities.